The full title of this lengthy piece is: "Fantasia a 4 voc. super Ich ruf' zu Dir, Herr Jesu Christ" written by Samuel Scheidt (1587-1654), part 1, nr. 13 of his Tabulatura Nova from 1624.
It's a very structured piece which is divided in four parts (the 4 phrases of this hymn).
Every part starts with a (kind of) fughetta on melodic fragments of the phrase, followed by 'Choralis in Cantu' (written for two voices), 'Choralis in Tenore' (written as a trio) and 'Choralis in Basso' (four part harmony).
Sometimes parts are repeated with a variation. The interludes are free but always with melodic fragments of the melody.
Wonderful music, I think :-)
Playing this music with a nice registration that emphasises the several parts was quite a puzzle and challenge. But an interesting journey too :-)
Played on the beautiful Krzeszow Engler instrument.